<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="message"></div>
</body>
<script src="../0.vendor/jquery-3.6.0.js"></script>

<script>
 /*  var message= document.getElementById('message');
   message.innerText = "hello";
   message.classList.add("box")*/

    $('#message').text('hello');
    $('#message').addClass('box');

</script>
</html>